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CN-121992429-A - Iridium alloy nanowire catalyst and preparation method and application thereof

CN121992429ACN 121992429 ACN121992429 ACN 121992429ACN-121992429-A

Abstract

The invention discloses an iridium alloy nanowire catalyst and a preparation method and application thereof. The iridium alloy nanowire catalyst comprises an active component and a carrier, wherein the active component is metal alloy Ir-M, the carrier is a conductive carrier, M is one or more of manganese, iron, cobalt, nickel, copper and zinc, and the morphology structure of the metal alloy Ir-M is worm-shaped multilayer nanowire. The iridium alloy nanowire catalyst provided by the invention not only can reduce the dosage of noble metal Ir and reduce the cost of the catalyst, but also can improve the electrochemical performance and the corrosion resistance of the catalyst.

Inventors

  • CHEN HAOSHEN
  • ZHANG TAO
  • TONG FENGYA
  • TIAN HAO
  • SONG LEI
  • MIAO CHANGXI

Assignees

  • 中国石油化工股份有限公司
  • 中石化（上海）石油化工研究院有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (14)

  1. 1. The iridium alloy nanowire catalyst is characterized by comprising an active component and a carrier, wherein the active component is metal alloy Ir-M, and the carrier is a conductive carrier, and M is one or more of manganese, iron, cobalt, nickel, copper and zinc; wherein, the morphology structure of the metal alloy Ir-M is a worm-shaped multilayer nanowire.
  2. 2. The catalyst of claim 1, wherein the nanowire has a diameter of 2.5-3.5 nm; and/or, the metal iridium in the metal alloy Ir-M is enriched on the surface, and the metal M is distributed in the metal alloy Ir-M; And/or the aspect ratio of the nanowire is higher than 2.
  3. 3. The catalyst according to claim 1, wherein M is selected from one or more of cobalt, nickel, copper, iron, preferably at least one of cobalt, nickel, copper; And/or the conductive carrier comprises one or more selected from carbon carriers, metal oxides and metal carbides, preferably carbon carriers; And/or the molar ratio of iridium metal to M metal in the active component is 1 (0.1-6), preferably 1 (0.3-5); And/or, based on the mass of the catalyst, the mass content of the metal alloy Ir-M in the iridium alloy nanowire catalyst is 15-90%, preferably 25-60%, and the mass content of the carrier is 10-85%, preferably 40-75%.
  4. 4. The catalyst of claim 1, wherein the active component of the catalyst is a polyhedral nanocrystal and the exposed crystal planes include (111), (100) and (110) crystal planes.
  5. 5. A process for preparing the catalyst of any one of claims 1-4, the process comprising: s1, mixing a reducing solvent, metal M salt, iridium salt, an organic coating auxiliary agent and a crystal face control reagent, performing hydrothermal reaction, and drying to obtain a metal alloy; And S2, loading the metal alloy obtained in the step S1 on a conductive carrier, and roasting to obtain the iridium alloy nanowire catalyst.
  6. 6. The preparation method of claim 5, wherein the step S1 specifically comprises the steps of mixing a reducing solvent, a metal M salt, an iridium salt, an organic coating auxiliary agent and a crystal face control reagent, carrying out hydrothermal reaction, adding a mixed solution of acetone and cyclohexane after the reaction to obtain a precipitate, filtering, washing and drying to obtain a metal alloy; And/or step S2 specifically comprises the steps of mixing the metal alloy obtained in step S1, the conductive carrier and the solvent, filtering, washing, drying and roasting to obtain the iridium alloy nanowire catalyst.
  7. 7. The method according to claim 5 or 6, wherein in step S1, the reducing solvent is at least one selected from the group consisting of a polyhydric alcohol, benzyl alcohol, and N, N-dimethylformamide; And/or in the step S1, the metal M salt is selected from at least one of chloride, bromide, nitrate, sulfate, acetate and acetylacetonate of the metal M, and the metal M is selected from one or more of manganese, iron, cobalt, nickel, copper and zinc; and/or, in the step S1, the iridium salt is selected from one or more of iridium chloride, iridium nitrate, iridium acetylacetonate, potassium chloroiridate, sodium chloroiridate and ammonium chloroiridate; And/or in the step S1, the organic coating auxiliary agent is selected from one or more of polyvinylpyrrolidone (PVP), propylene glycol methyl ether acetate (PMA) and polyphthalamide (PPA); And/or, in step S1, the crystal face control reagent is a coordination reagent containing I-, preferably at least one selected from potassium iodide, sodium iodide, potassium iodate and sodium iodate.
  8. 8. The preparation method according to claim 5 or 6, wherein in the step S1, the molar ratio of the iridium salt to the metal M salt calculated as iridium to the metal M calculated as M is 1 (0.1-6); And/or in the step S1, the mass ratio of the reducing solvent to the organic coating auxiliary agent to the sum of the mass of the metal M salt and the iridium salt is (100-1000): 1-9): 1; And/or in the step S1, the iridium salt is calculated by iridium, and the molar ratio of the crystal face control reagent to the iridium salt is (0.5-8) 1; And/or in the step S1, the operation condition of the hydrothermal reaction is that the temperature is 100-250 ℃, the time is 2-36 h, and the pressure is 0.1-1.2 MPa.
  9. 9. The preparation method of claim 6, wherein in the step S1, the volume ratio of the acetone to the cyclohexane is 1 (2-5), and the dosage ratio of the mixed solution of the acetone and the cyclohexane to the iridium salt is 1mg (2-5).
  10. 10. The method of claim 5, wherein in step S2, the conductive support comprises one or more selected from the group consisting of a carbon support, a metal oxide, and a metal carbide; And/or in step S2, the solvent is selected from one or more of absolute ethanol, acetone, ultrapure water, and methanol; And/or in the step S2, the using amount and mass ratio of the metal alloy to the conductive carrier are (15-90): (10-85); And/or in the step S2, the roasting operation condition is that the temperature is 100-800 ℃, the time is 1-6 h, and the atmosphere is oxygen-containing gas.
  11. 11. Use of the catalyst of any one of claims 1 to 4 and/or the catalyst obtained by the process of any one of claims 5 to 10 in an electrochemical system.
  12. 12. The use according to claim 11, wherein the electrochemical system is an electrolyzed water system.
  13. 13. The use according to claim 12, wherein the electrolyzed water system comprises proton exchange membrane electrolyzed water, acid electrolyzed water; And/or the application is an oxygen evolution reaction under acidic conditions, preferably an anodic oxygen evolution reaction for electrolysis of water under acidic conditions.
  14. 14. The use according to claim 13, wherein the oxygen evolution reaction under acidic conditions comprises an oxygen evolution reaction occurring at the surface of the polymer electrolyte membrane and in an acidic solution; And/or the polymer electrolyte membrane comprises at least one of a perfluorinated sulfonic acid proton membrane, a partially fluorinated polymer proton membrane, a non-fluorinated polymer proton membrane and a composite membrane.

Description

Iridium alloy nanowire catalyst and preparation method and application thereof Technical Field The invention belongs to the field of electrocatalysis, and particularly relates to an iridium alloy nanowire catalyst, a preparation method and application thereof. Background Hydrogen (H 2) is considered to be an ideal energy carrier due to its high energy density, green cleaning and other characteristics. However, as a secondary energy source, H 2 is mainly prepared by reforming fossil energy, and the use of fossil energy cannot be reduced fundamentally. In contrast, the technology of hydrogen production by electrolysis of water uses electrical energy to directly decompose water into H 2 and O 2. The energy can be provided by intermittent green energy (such as solar energy, wind energy, tidal energy and the like), and the use of fossil energy and the emission of greenhouse gases are avoided in the whole process. CN116876013a discloses a tin-nickel alloy catalyst, which utilizes bi-metal synergistic catalysis to improve electron transfer capability and has ultra-high OER activity. However, the catalyst does not contain noble metal, is entirely composed of transition metal, is easily corroded and deactivated under the acidic condition of electrolytic water, and has poor durability. An ideal catalyst for the more slowly dynamic anodic oxygen evolution reaction (oxygen evolution reaction, OER) in the electrolyzed water reaction is iridium oxide or ruthenium oxide. Among them, iridium catalysts are attracting attention due to their high activity and good corrosion resistance. Iridium catalysts have many advantages in oxygen evolution reactions, exhibit excellent electrocatalytic activity, and have excellent corrosion resistance and stability. However, iridium catalysts also have some problems. Iridium, a rare and expensive metal, has limited its popularity in large-scale applications. For example, CN110453256B discloses an electrochemical deposition method for preparing polyhedral cobalt iridium nanoparticle catalysts, but the method is costly and the size of the obtained catalyst particles is not good for providing electrochemically active sites. Therefore, how to reasonably design an Ir-based catalyst, enhance the corrosion resistance of the Ir-based catalyst while improving the catalytic activity and maintain the electrochemical performance under the acidic strong oxidation condition becomes a very practical topic. Disclosure of Invention The invention provides an iridium alloy nanowire catalyst and a preparation method and application thereof, and aims to solve the problems that in the prior art, the catalytic activity is insufficient, the catalyst is easy to corrode, the cost is too high and the like in an anodic oxygen evolution reaction. The iridium alloy nanowire catalyst provided by the invention not only can reduce the dosage of noble metal Ir and reduce the cost of the catalyst, but also can improve the electrochemical performance and the corrosion resistance of the catalyst. The first aspect of the invention provides an iridium alloy nanowire catalyst, which comprises an active component and a carrier; The active component is metal alloy Ir-M, the carrier is conductive carrier, M is one or more selected from manganese, iron, cobalt, nickel, copper and zinc; wherein, the morphology structure of the metal alloy Ir-M is a worm-shaped multilayer nanowire. Further, the diameter of the nanowire is 2.5-3.5 nm. Preferably, the aspect ratio of the nanowires is higher than 2. Further, the distribution of the metal iridium and the metal M in the metal alloy Ir-M is different, wherein the metal iridium is distributed on the surface of the alloy structure more intensively than the metal M, and the metal M is distributed more inside in the alloy structure, so that the metal iridium is concentrated on the surface and the metal M is distributed inside in the metal alloy Ir-M. The metal distribution of the alloy structure can play a role in improving the performance and simultaneously resisting acid corrosion. Further, the worm-like multi-layered nanowire refers to a multi-layered nanowire structure which is formed by iridium and metal M alternately extending and presents worm-like. Further, the M is preferably one or more selected from cobalt, nickel, copper and iron, more preferably at least one of cobalt, nickel and copper, and even more preferably cobalt and/or nickel. Further, the conductive carrier includes one or more selected from the group consisting of a carbon carrier, a metal oxide, and a metal carbide, preferably a carbon carrier, more preferably one or more of carbon black XC-72, and carbon black BP 2000. Further, the molar ratio of iridium metal to M metal in the active component is 1 (0.1-6), preferably 1 (0.3-5), more preferably 1 (0.5-2). Further, the mass content of the metal alloy Ir-M in the iridium alloy nanowire catalyst is 15-90%, preferably 25-60%, and the mass content of the carrier is 10-85%, p